Photo by: ArtMechanic Creative Commons Newtonian telescope is a kind of reflecting telescope that has a concave primary mirror and a flat secondary mirror. It is patterned after the telescope invented by Sir Isaac Newton, the famous British astronomer and scientist who during the 17th century.
Photo by: Tamasflex Creative Commons The eye relief is an important concept in the use of equipments like a telescope, microscope, or binoculars. By definition, eye relief is the distance from the eye piece at which the eye can be placed to the entrance pupil of the eye. Instruments with short eye relief will require […]
When looking through the eyepiece of a telescope, a variety of field of view can be seen. The field of view is the area that can be seen through the eyepiece and is measured in angular diameter. Different factors cause the variations in the field of view such as the magnification, field stop of the […]
Photo by: Ligar Creative Commons In physics, focus is defined as that point in which the rays of light converge or meet; or diverge in the case when light is refracted or reflected. In optics, it can mean a number of things including: ? A lens? focal point ? A lens? or a telescope?s eyepiece?s […]
Photo by: Tamasflex Creative Commons If you recently have had a conversation with an astronomer, then you’ve probably heard them mention the exit pupil as a certain eye piece in telescopes or binoculars. But what does exit pupil really mean, and how can it affect views when looking through a telescope?
What is a telescope Lens? A telescope Lens comes in different sizes. One may find one in the form of a small plastic toy; another may find a telescope Lens that is worth millions of dollars. There are telescopes found in science laboratories all over the globe, there are telescopes in observatories, there are even […]
Light-gathering power is a way to measure the performance and effectiveness of a telescope that is proportionate to the square root of the size of the aperture. For instance, a telescope that possesses more than two times its diameter has the potential to collect about four times as many light.
Focal ratio is also commonly known as the f/number, f/ratio, f-stop, f-ratio, etc; and is notated simply as N. Focal ratio is the speed by which an optical system needs to be exposed to produce an image; and can be found by dividing the system?s focal length by its aperture. A lower focal ratio means […]
In astronomy, field of view (FOV) is the amount of sky seen by the naked eye or through a telescope. This commonly refers to the angular area viewed by a telescope or any high magnification instrument; and is usually measured in square degrees, or for higher magnification instruments, in square arc-minutes. Separated from a telescope, […]
In astronomy, focal length is primarily used when referring to telescopes. It is the distance light travels starting from the lens of a telescope down to the point where it is focused. While in optics, focal length is simply defined as the strength by which an optical system (like a telescope) converges (focuses) or diverges […]